"Federal officials announced two major settlements on Thursday for reducing emissions from 28 glass and cement plants across the country.

The plants were found to be violating the Clean Air Act by emitting excessive amounts of sulfur dioxide, nitrogen oxides and particulate matter each year, said Cynthia Giles, assistant administrator for the Environmental Protection Agency’s office of enforcement and compliance assurance.

Each company will spend more than $100 million in installing pollution control equipment to lower emissions, the E.P.A. and the Justice Department said. Together the two will also pay a combined $7.2 million in fines.